J-2X engine test at Stennis Space Center on April 26, 2012. (NASA/SSC)View large image NASA kicked off the next round of testing on the J-2X rocket engine April 26, gathering data on the performance of the newly-installed engine nozzle extension and test stand "clamshell" as well as on the engine start and shutdown sequences.

The test on the A-2 Test Stand at NASA's Stennis Space Center begins a second, more extensive round of testing for the next-generation engine selected as part of the Space Launch System that will carry humans deeper into space than ever before. It was the first test with the J-2X nozzle extension installed on the engine and the first with the new clamshell equipment built for the J-2X and installed on the A-2 stand. The changes allow operators to test the engine at simulated altitudes up to 50,000 feet.

The J-2X is being developed by Pratt & Whitney Rocketdyne for NASA's Marshall Space Flight Center in Huntsville, Ala. It is the first liquid oxygen and liquid hydrogen rocket engine rated to carry humans into space to be developed in 40 years. The J-2X will provide upper-stage power for NASA's Space Launch System, a new heavy-lift vehicle capable of missions beyond low-Earth orbit.

Watch the J-2X engine test below:[image-47]

The space agency conducted an initial round of sea-level tests on the engine last year, then removed it from the Stennis test stand to prepare both stand and engine for the second round of simulated high-altitude testing. Such testing is critical; the J-2X with nozzle extension needs to prove it can perform at altitude as needed for SLS.